Flashgal is an action game with automatic side scrolling, in which you control an heroine who will have to get rid of enemies of all kind, including gangsters, samurais, ninjas, dogs, robotic birds, etc. Most of the levels will develop as a one-plane beat 'em up, but there will also be sections which play as a regular shoot 'em up with horizontal scrolling, plus others in which you will drive a motorcycle or a jet ski which have the ability to shoot missiles upwards and jump obstacles.
There are eleven unique levels, although in the course of the game many of these levels will reappear. Your lifebar, named "power" in-game, decreases as you get hit, but also recovers itself as you defeat thugs and jump over obstacles. Also, in some levels (the non-vehicle ones) you will be able to use other weapons besides your body, these including the katana, which you wear on one level, and the gun with infinite ammo, which can be obtained on several levels by grabbing the item you get after defeating a green ostrich.